Grace Gardner, Joe Buchanan, Casey Kristofferson Pond Zooplankton Analysis at OX Ranch
Outline Background Methods Data Results Management Summary
Background Purpose of ponds Macrophytes Location- middle pond Zooplankton Assessment October 7 th and 8th
Methods Onshore vs. Offshore Equipment Sampling Lab Analysis Reasoning
X X X X X X Black X: Offshore sites Gray X: Onshore sites Volume of offshore= m^3 Volume of onshore =1300 m^3 Onshore vs. Offshore
vesr.ucnrs.org wildco.com Sampling
Reasoning: Daphnia Pond Community Role of Daphnia
Data and Results Comparisons of Offshore and Onshore zones – Abundances of all Zooplankton genera present – Average length of zooplankton – Average length of Daphnia specifically – Average biomass of Daphnia – If time permits: abundances between night and day within the offshore zone
Large-bodied Daphnia benefits Burns et al. 1968, found a correlation between length of zooplankton and diameter of particle able to filter This means that the larger-bodied zooplankton within onshore zone are providing top-down control upon algal blooms Management implications with removal of these zooplankton (Burns 1968)
ParametersPond Total Daphnia Biomass (mg/L) Daphnia Abundance (#/L) Daphnia Average Length (mm) Zooplankton Length (mm) Daphnia length range: mm
Management Ox Ranch Plan Suggestions Role of management plan
Pond Status Pond is in great condition for Daphnia. High densities of Macrophytes Good for daphnia Bad for fish
Management Suggestion Macrophyte removal Dredging Fish habitat Fish stocking Shading Role
Macrophyte Removal Remove 30-40% of macrophytes Mostly near/around dock Significance
Dredging 3 meters deep In front of dock Depth for fish habitat
Fish habitat Brush piles in open water In dredging area Christmas trees, brush, anything. (Bassett et al. 1994)
Stocking Conservative Fish population boom at beginning Ecosystem reaction
Shading Plant willows Shading of pond Bank stabilization
Role of Management plan Economically effective Maintain balance Supply fishing opportunities
Summary Background Methods Data Results Management Questions?
Citations Bassett, C. E Use and evaluation of fish habitat structures in lakes of the eastern United States by the USDA Forest Service. Bulletin of Marine Science, 55: Burks, R.L., Jeppersen, E., and Lodge, D.M Littoral zone structure as Daphnia refugia against fish predators. Limnology and Oceanography 46: Burns, C.W The relationship between body size of filter-feeding cladocera and the maximum size of particle ingested. Limnology and Oceanography 13: Wetzel, R.G Limnology. 3 rd Ed. Academic Press, San Diego, CA, U.S.A.